I have seen many citations of California codes that say things like 'VC § 1234', 'CVC § 1234', "vc sec. 1234", "cvc section 1234" etc, when referring to the Vehicle Code. I've also seen the same style used with "WIC" for the Welfare and Institutions Code, and "PC" for the Penal Code.
I cannot find any style guide that explains citations in the above manner. Instead the guides I find would say "Veh. Code", "Welf. & Inst. Code", "Pen. Code" etc. Is there a style guide that uses the first style I mentioned, even an antiquated one, or are instances of the first style entirely ad hoc?